Lubricant



Patented Sept. 26, 1939 PATENT OFFICE LUBRICANT Frederick W. Sullivan,Jr., Flossmoor, Ill., assignor to Standard Oil Company, Chicago, 111., acorporation of Indiana No Drawing.

Application November 27, 1936,

Serial No. 112,985 6 Claims. (01. 87-9) This invention relates tolubricants and, in particular, to addition agents imparting tolubricants improved properties.

My invention has particular utility in preventing and/or inhibiting thecorrosion of hard metal alloy bearing such as copper-lead,cadmium-nickel, and cadmium-silver bearings which, to a large extent,have replaced soft metal bearingssuch as Babbitt metal in the trendtoward internal combustion engines having high compression ratios andincreased acceleration and increased speed characteristics. The use ofthe hard metal bearings has created lubricating and corrosion .probiems,particularly in connecl tion with highly refined oils, some of which maybe very corrosive to the hard metal" bearings.

By highly refined lubricating oils I mean vis cous oils which have aminimum viscosity in the 0 range of S. A. E. 10 oils, and which havebeen subjected to such refining processes such as, for example, solventextraction, that the parafiinicity of the oil is markedly increased. Ithas been found that highly refined lubricating oils cause corrosion toalloy bearings of the cadmium silver type to the extent of 5 mg/cm andeven greater when such bearings are submerged for 25 hours or less in anair agitated oil which has been preoxidized at about 340 F. for 25 to 50hours.

i The motor oils may be highly refined lubricating oils as such ormixtures of highly refined lubrieating oils with less'highly refinedlubricating oils, or stated in another way, mixtures of corrosive oilsand non-corrosive oils, examples of the latter being lubricating oilfractions from Winkler crude or crudes of the Winkler type.

My invention is practised by adding to highly refined lubricating oilsup to 5%, but preferably from 0.0005 to 0.01 gram mols to 100 grams ofoil of certain organic phosphorous compounds derived from phosphinic andphosphinous acids, said organic phosphorous compounds having the generalformula 2 xiv in which R and R" are hydrocarbon radicals such as alkyl,aryl, aralkyl or alkaryl or mixtures thereof and/or said hydrocarbonradicals having substituted mercapto, hydroxy, amino, alkyl substitutedamino, thiocyano, isothiocyano, or halogen group or groups; X is oxygen,sulfur or selenium; Z is either absent or is oxygen, sulfur,

in which R, R and X are as defined above:

Diethyl isoamyl thiophosphinite Diamyl methyl phosphinite Diethylpropylphosphinite Diethyl phenylphosphinite Diethylphenylthiophosphinite Diphenyl ethylphosphinite Dithiophenylethylphosphinite Di isobutyl phenylthiophosphinite Diethylchlor-phenylphosphinite The following compounds are examples of theesters of the di R-phosphinous acid having the eneral formula in whichR, R" and X are as hereinbefore defined:

Ethyl diphenylphosphinite Ethyl diphenylthiophosphinite Isopropyldiphenylthiophosphinite Iso diphenylphosphinite Amyl diamylphosphiniteIsoamyl dibutylthiophosphinite Phenyl diphenylphosphinite Phenyldiphenylthiophosphinite Listedbelow are specific examples of the diesters of R-phosphinic acid having the general formula in which R", R",X are as hereinbefore defined and Z is oxygen, sulfur or selenium:

Diethyl phenylphosphinate Diethyl paratolylphosphinate Dibutyl m-carboxyphenylphosphinate Diethyl p-bromo phenylphosphinate Dimethyl alphahydroxy benzylphosphinate Dibutyl alpha hydroxy isopropylphosphinate Diisoamyl hydroxy methylphosphinate.

in which R The esters of the di R-phosphinic acid having the generalformula I '):-P( in which R, R", X are as hereinbefore defined and Z isoxygen, sulfur or selenium are illustrated by the. followingrepresentative compounds:

Ethyl phenylethylphosphinate Ethyl diphenylphosphinate Ethyl 4-methyl-4carboxy diphenylphosphinate Butyl di-p-tolylthiophosphinate Methylphenylmethylphosphinate Amyl phenylhydroxyethylphosphinate, etc.

Compounds such as ethyl phenylphosphinate, butyl isoamyl thiophosphinateare examples of the mono esters of the R-phosphinic acid having thegeneral formula,

in which R and R" are as hereinbefore defined, contemplated within thescope of my invention. Contemplated within the scope of my invention arealso the mono esters of the R-phosphinous acid having the generalformula and R" are as hereinbeiore defined. Examples of such compoundsare ethyl phenylphosphinite and phenyl butyl phosphinite.

In addition to the compounds hereinbefore mentioned my invention furthercontemplates the use of the isomers of the di R-phosphinous acid havingthe general formula R nh X in which R, R" and X are as hereinbeforedefined. Examples of compounds falling within this class are:

As has been heretofore mentioned many of the 'recent models ofautomobiles now in use are equipped with bearings of the hard metal"alloy type such as cadmium-silver alloy, cadmiumnickel alloy,nickel-lead alloy, etc. for the purpose of permitting increased speedcharacteristics and increased acceleration. In recent years minerallubricating oils adapted for use in internal combustion engines havebeen given refining treatments, such as solvent extraction, which aremore drastic than those of the past, for the purpose of increasing theviscosity index of such oils. While oils so refined give satisfactoryperformance in many respects, they have been found to cause more or lesstrouble in internal combustion engines equipped with bearings of thecadmiumsilver type due to the corrosion of such alloys. This conditionis remedied by the addition of very small amounts, such as 0.0005 to0.01 gram mols per grams of oil of any of the foregoing compounds ormixtures thereof to corrosive highly refined motor oils will inhibit thecorrosion of the hard metal alloy bearings.

My invention further contemplates the use of the foregoing compounds inconcentrations up to 10% in oils whether highly refined or not for thepurpose of improving the film strength of said oils and to impart tolubricants improved extreme pressure characteristics. These compoundsmay also be used to impart other desirable properties to lubricatingoils such as nonsticking ring properties and the like.

Some of the hereinbefore named compounds may not be completely solublein the lubricant, in which case effective results may be obtained bysuspending the inhibitor in the lubricant and by means of a small amountof a peptizlng agent such as aluminum naphthenate, aluminum stearate andthe like.

I do not wish to limit myself to'the specific embodiments of myinvention herein described except as defined by the appended'claims.

I claim: 1

1. A corrosion inhibited motor oil comprising a mineral lubricating oiland a small amount but not more than 5% of an ester of phosphinous acidhaving the general formula (R).-P(XR)|,

' in which R and R" represent members selected from the group consistingof alkyl, aryl, aralkyl, alkaryl and halogen-substituted alkyl, aryl andaralkyl groups; X is an element selected from the group consisting ofoxygen, sulfur and selenium; a and b are integers selected from thegroup of numbers consisting of l and 2; and in which a+b is always equalto 3.

2. A corrosion inhibited motor oil comprising a mineral lubricating oiland a small amount but not more than 5% of an ester of phosphinic acidhaving the general formula in which R and R" represent members selectedfrom the group consisting of alkyl, aryl, aralkyl. alkaryl andhalogen-substituted alkyl, aryl and aralkyl groups; Z is an elementselected from the group consisting of oxygen, sulfur and selenium; X isan element selected from the group consisting of oxygen, sulfur andselenium; a and b are integers selected from the group of numbersconsisting of l and 2; and in which (1+!) is always equal to 3.

3. The method of preventing the corrosion of metal alloy bearingsselected from the group consisting of cadmium-silver,-cadmium-nickel,copper-lead alloys in the presence of highly refined lubricating oils ininternal combustion engines which comprises adding an ester ofphosphinous acid having the general formula lenium; a and b are integersselected from the group of numbers consisting of l and 2; and in whicha+b is always equal to 3, said esters being added in a small butsufilclent quantity to inhibit the corrosion of said metal alloybearings.

4. The method of preventing the corrosion of metal alloy bearingsselected from the group consisting of cadmium-silver, cadmium-nickel andcopper-lead alloys of the cadmium-silver al- 1 (R) P(XR) a in which Rand R" represent members selected from the group consisting of alkyl,aryl, aralkyL- alkaryl and halogen-substituted alkyl, aryl and aralkylgroups; Z is an'element selected from the group consisting of oxygen,sulfur and selenium; X is an element selected from the group consistingof oxygen, sulfur and selenium; a and b are integers selected from thegroup of numbers consisting of 1 and 2; and in which a+b-is always equalto 3, said esters being added in small but sumcient quantities to retardthe corrosion to said metal alloy bearings.

5. A corrosion inhibited motor oil comprising a mineral lubricating oiland a small amount but not more than 5% of a mono ester of a substitutedphosphinic acid having the general formula in which R and R" areradicals selected from the group consisting of alkyl, aryl, aralkyl,alkaryl and halogen substituted alkyl and aryl radicals.

6. A corrosion inhibited motor oil comprising a mineral lubricating oiland an organic phosphorous compound selected from the group consistingof compounds having the general formulas in which R and R" representmembers selected from the group consisting of alkyl, aryl, aralkyl,alkaryl and halogen-substituted alkyl, aryl and aralkyl groups; Z is anelement selected from the group consisting of oxygen, sulfur andselenium; X is an element selected from the group consisting of oxygen,sulfur and selenium; a and b are integers selected from the group ofnumbers consisting of 1 and 2; c is a number selected from the group ofnumbers consisting of and 1; and in which a+b+c is always equal to 3,said organic phosphorous compound being added in small but suflicientquantities to inhibit corrosion by said mineral lubricating oil.

FREDERICK W. SULLIVAN, JR.

CERTIFICATE OF CORRECTION.

Patent No. 2,l7Li,Ol9.v

September 26, 1959.

FREDERICK w. SULLIVAN, JR.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,0nd column, line YE, and page 5, first column, line 1, claim ii,

sec-

strike out the words "of the cadmium-silver alloy type; and that thesaid letters Patent shouldbe read with this correction therein that thesame may conform to the record of the case in the Patent Office. I

Signedand sealed this 51st day of October, A. D. 1959.

(Seal) Henry Van Arsdale, Acting Commissioner of Patents.

